With the development of information technology, demands of mass data impose new challenges to storage performance of a system, and a performance enhancement measure is to apply cache media in devices.
In the prior art, a block storage-based data processing system generally employs a 1+N mode, that is, one service processing node responsible for processing services and N JBOD (Just a Bunch Of Disks, just a bunch of disks), as illustrated in FIG. 1. The service processing node includes two controllers, and a cache medium located in each controller that implements a read and write caching function for the JBOD. The controllers are connected to each other over a peripheral component interconnect express (PCI Express, abbreviated as PCI-E) channel, and data is transmitted between the controllers over the PCI-E channel. The controller is connected to the JBOD over a limited number of serial attached small computer system interface (Attached Small Computer System Interface, abbreviated as SAS) channels. When a large number of disks (DISK) need to be extended, due to the limited number of SAS channels, JBOD cascading is typically employed.
In the prior art, during JBOD extension in the block storage-based data processing system, the capacity of the cache medium in the service processing node needs to be accordingly increased. With respect to the cache medium, its scalability is limited by the development of hardware technologies, and becomes a bottleneck, restricting the practical function thereof. The prior art fails to provide an effective mechanism to solve the problem.